color.py

import numpy as np
import cv2

COLOR_ROWS = 80
COLOR_COLS = 250
capture = cv2.VideoCapture(0)
if not capture.isOpened():
    raise RuntimeError('Error opening VideoCapture.')

(grabbed, frame) = capture.read()
snapshot = np.zeros(frame.shape, dtype=np.uint8)
cv2.imshow('Snapshot', snapshot)

colorArray = np.zeros((COLOR_ROWS, COLOR_COLS, 3), dtype=np.uint8)
cv2.imshow('Color', colorArray)
def on_mouse_click(event, x, y, flags, userParams):
    if event == cv2.EVENT_LBUTTONDOWN:
        colorArray[:] = snapshot[y, x, :]
        rgb = snapshot[y, x, [2,1,0]]
        
        
        luminance = 1 - (0.299*rgb[0] + 0.587*rgb[1] + 0.114*rgb[2]) / 255
        if luminance < 0.5:
            textColor = [0,0,0]
        else:
            textColor = [255,255,255]

        cv2.putText(colorArray, str(rgb), (20, COLOR_ROWS - 20),
            fontFace=cv2.FONT_HERSHEY_SIMPLEX, fontScale=0.8, color=textColor)
        cv2.imshow('Color', colorArray)

cv2.setMouseCallback('Snapshot', on_mouse_click)

while True:
    (grabbed, frame) = capture.read()
    cv2.imshow('Video', frame)

    if not grabbed:
        break

    keyVal = cv2.waitKey(1) & 0xFF
    if keyVal == ord('q'):
        break
    elif keyVal == ord('t'):
        snapshot = frame.copy()
        cv2.imshow('Snapshot', snapshot)

capture.release()
cv2.destroyAllWindows()